Just before he reached the dark side on the third orbit, Mission Control informed Collins that there was a problem with the temperature of the coolant. If it became too cold, parts of Columbia might freeze. Mission Control advised him to assume manual control and implement Environmental Control System Malfunction Procedure 17. Instead, Collins flicked the switch on the offending system from automatic to manual and back to automatic again, and carried on with normal housekeeping chores such as dumping excess water produced by the fuel cells, while keeping an eye on the temperature. When Columbia came back around to the near side of the Moon again, he was able to report that the problem had been resolved.
Rebooting works…even in space!